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Biomedical subjects

H Präuer

Publications and source records attributed to H Präuer.

At least 19 recordsLinked to original sources
PubMed2004

Factors influencing survival after resection of pulmonary metastases from colorectal cancer.

BACKGROUND: Selection of patients for resection of lung metastases from colorectal cancer is problematic. The aim of this study was to evaluate clinically relevant prognostic factors and to define a subgroup of patients who would most benefit from such surgery. PATIENTS: Seventy-five patients (median age 58 (range 33-82) years) with pulmonary metastases from colorectal cancer underwent 104 R0 lung resections. Median follow-up was 33 (range 4-116) months. Patients who had no evidence of recurrent extrathoracic disease, no more than three metastases on either side, lobectomy as the maximal surgical procedure, and adequate cardiorespiratory function were eligible for surgery. Univariate and multivariate Cox regression, and classification and regression tree subgroup analyses were performed. RESULTS: Overall median survival was 33 months, with 3- and 5-year survival rates of 47 and 27 per cent respectively. Size of metastases (relative risk (RR) 2.6) and extent of resection (RR 0.4) were identified as independent prognostic factors. Primary tumour stage was significant in univariate analysis. Subgroup analysis defined two statistically relevant prognostic groups: patients with a maximum metastasis size of 3.75 cm or less with a disease-free interval of more than 10 months and patients with larger metastases and a shorter disease-free interval. Median survival and 5-year survival were 45 months and 39 per cent in the former group, and 24 months and less than 11 per cent in the latter. CONCLUSION: Subgroup analysis provided criteria for the selection of patients for R0 resection of lung metastases from colorectal cancer and differentiated between those at high or low risk of early tumour progression; the latter patients would benefit most from surgery.

Adult↗
PubMed2001

Extended resection of a chest wall desmoid tumour with concomitant coronary artery bypass grafting.

We report on the resection of a large desmoid tumour of the anterior chest wall in a 65-year-old male patient. The patient had a coronary artery bypass operation 2 years prior to the first detection of a tumour. Because the left internal mammary artery bypass to the left anterior descending coronary artery (LAD) was embedded in the tumour mass, it had to be resected together with the tumour. A saphenous vein aorto-coronary bypass to the LAD with an off-pump technique was then performed, and the chest was reconstructed with polypropylene mesh and a latissimus dorsi musculocutaneous flap.

Aged↗
PubMed1997

p53 alterations in thymic epithelial tumours.

The prognosis of thymic epithelial tumours depends on malignant behaviour that cannot always be predicted on histological grounds. This study aimed at identifying a molecular marker that would be useful in overcoming the drawbacks of histopathology. Forty-four thymic epithelial tumours were analysed for alterations of the tumour suppressor gene p53 using immunohistochemistry (antibodies D0-1 and CM-1) and PCR-based single-strand conformation polymorphism and DNA sequencing. Histological and clinical evaluation and also p53 analysis revealed three major tumour groups: non-organotypic thymic carcinomas with frequent p53 alterations (7/9) and occurrence of p53 gene mutations (2/9); malignant thymomas with frequent p53 alterations but without p53 gene mutations (11/18); and benign thymomas with rare p53 alterations and without p53 gene mutations (2/17). In non-organotypic thymic carcinomas p53 was detected with both antibodies. In contrast, thymomas lacked immunoreaction with D0-1 suggesting alteration of the antibody-binding site. Overall immunohistochemical results correlated with clinical stages (P < 0.01), pathohistology (P < 0.01), and survival times (P < 0.05). We consider immunohistochemical p53 detection to be a useful new prognostic factor for the evaluation of thymic epithelial tumours.

Adult↗
PubMed1997

Effects of beta 2-agonist- and dexamethasone-treatment on relaxation and regulation of beta-adrenoceptors in human bronchi and lung tissue.

1. Long-term treatment with beta 2-adrenoceptor agonists can lead to a decreased therapeutic efficacy of bronchodilatation in patients with obstructive pulmonary disease. In order to examine whether or not this is due to beta-adrenoceptor desensitization, human bronchial muscle relaxation was studied in isolated bronchial rings after pretreatment with beta 2-adrenoceptor agonists. Additionally, the influence of pretreatment with dexamethasone on desensitization was studied. 2. The effect of beta 2-agonist incubation alone and after coincubation with dexamethasone on density and affinity of beta-adrenoceptors was investigated by radioligand binding experiments. 3. In human isolated bronchi, isoprenaline induces a time- and concentration-dependent beta-adrenoceptor desensitization as judged from maximal reduction in potency by a factor of 7 and reduction of 73 +/- 4% in efficacy of isoprenaline to relax human bronchial smooth muscle. 4. After an incubation period of 60 min with 100 mumol l-1 terbutaline, a significant decline in its relaxing efficacy (81 +/- 8%) and potency (by a factor 5.5) occurred. 5. Incubation with 30 mumol l-1 isoprenaline for 60 min did not impair the maximal effect of a subsequent aminophylline response but led to an increase in potency (factor 4.4). 6. Coincubation of dexamethasone with isoprenaline (120 min; 30 mumol l-1) preserved the effect of isoprenaline on relaxation (129 +/- 15%). 7. In radioligand binding experiments, pretreatment of lung tissue for 60 min with isoprenaline (30 mumol l-1) resulted in a decrease in beta-adrenoceptor binding sites (Bmax) to 64 +/- 1.6% (P < 0.05), while the antagonist affinity (KD) for [3H]-CGP-12177 remained unchanged. 8. In contrast, radioligand binding studies on lung tissue pretreated with either dexamethasone (30 mumol l-1) or isoprenaline (30 mumol l-1) plus dexamethasone (30 mumol l-1) for 120 min did not lead to a significant change of Bmax (160 +/- 22.1% vs 142.3 +/- 28.7%) or KD (5.0 nmol l-1 vs 3.5 nmol l-1) compared to the controls. 9. In conclusion, pretreatment of human bronchi with beta-adrenoceptor agonists leads to functional desensitization and, in lung tissue, to down-regulation of beta-adrenoceptors. This effect can be counteracted by additional administration of dexamethasone. Our model of desensitization has proved useful for the identification of mechanisms of beta-adrenoceptor desensitization and could be relevant for the evaluation of therapeutic strategies to counteract undesirable effects of long-term beta-adrenoceptor stimulation.

Adrenergic beta-2 Receptor Agonists↗
PubMed1993

Infrequent mutations of the p53 gene in pulmonary carcinoid tumors.

Archival specimens of 25 pulmonary carcinoids including 15 cases of typical carcinoid, 9 atypical carcinoids, and 1 large-cell neuroendocrine carcinoma were analyzed for mutations in exons 5 to 8 of the p53 gene. Mutations were identified in 4 tumors, including 3 out of 15 (20%) typical carcinoids and the single large-cell neuroendocrine carcinoma, but none of the atypical carcinomas showed a mutation. The mutations were acquired during tumor development since they were not present in the corresponding nontumorous tissue. All mutations in the typical carcinoids, a tumor type without epidemiological link to cigarette smoking, were G to A transitions. The level of p53 protein was investigated by immunohistochemistry with the polyclonal antibody CM-1. None of the pulmonary carcinoids investigated showed a positive reaction, despite the presence of missense mutations in two cases. Negative staining of carcinoids with mutations was also observed with the monoclonal antibodies pAb1801 and DO-1. Our data suggest that point mutations of the p53 gene are infrequent in pulmonary carcinoids thus contrasting the findings in other histological types of lung cancer, in particular small-cell lung cancer. Moreover, negative immunostaining for p53 is no indicator for the absence of p53 missense mutations in typical carcinoids.

Adult↗
PubMed1993

Mutational spectrum of the p53 gene in human small-cell lung cancer and relationship to clinicopathological data.

The spectrum of p53 gene mutations was determined in formalin-fixed, paraffin-embedded samples of small-cell lung cancer derived from 28 patients. By direct sequencing of exons 5, 7, and 8, including their flanking intron sequences, 18 mutations were identified in 17 tumors (61%), and in all but two of these the wild type allele was lost. In 8 cases, the mutation detected in the tumor was absent from the corresponding normal tissue, indicating that these mutations were somatically acquired. In two patients, identical mutations were found in the primary tumor and corresponding metastases. In a further case, an intrapulmonary metastasis did not show the mutation detected in the primary tumor. The local distribution of the mutations resembled that reported in non-small cell lung cancer and gave no indication of distinct bot spot regions. G-to-T transversions were the predominant type of mutation, reflecting a possible genotoxic influence of carcinogens contained in tobacco smoke. Mutations were equally distributed among tumors with intermediate and oat cell histology and did not show a significant association to age and gender of the patients. Also, no significant relationship was observed between the presence of a mutation and tumor stage (T, N, M) or survival. However, transitions at CpG dinucleotides were restricted to tumors without detectable metastases at the time of biopsy, whereas all other mutations occurred in metastasizing small cell lung cancer.

Base Sequence↗
PubMed1991

[Long-term results of multimodality therapy of small cell bronchial cancer including surgery].

The results of a prospective Phase II study of a multimodal treatment regimen including surgery of operable stages of small cell lung cancer are reported. Of 45 patients 24 received all parts of the projected treatment. The 5-year survival probability is 56% and 8 patients are still living after more than 60 months. Eleven patients with N2 lymph node metastases receiving the complete therapy have a projected 5-year survival of 60%.

Austria↗
PubMed1989

[Enoxacin concentrations in lung tissue].

For successful treatment of bacterial lung infections the administered antibiotic must reach sufficiently high concentrations in lung tissue. Therefore, the concentrations of enoxacin in this tissue were measured in ten patients requiring pulmonary surgery. In order to prevent postoperative infection, the patients received 400 mg enoxacin b.i.d. for three days. Eight h after the final dose samples of venous blood were drawn and a sample of lung tissue was removed. Using a microbiological assay, we found the following concentrations (mean +/- S.D.):serum 2.36 (+/- 0.65) mg/l, lung 6.48 (+/- 1.54) mg/kg. With the HPLC-technique the corresponding values method were 2.37 (+/- 0.80) mg/l and 7.41 (+/- 3.01) mg/kg. Thus concentrations of enoxacin in lung tissue are about three times higher than the corresponding serum concentrations.

Aged↗
PubMed1988

[Peripheral pulmonary stenosis: initial manifestation of a malignant teratoma].

A case of acquired pulmonic stenosis is described. The only symptoms reported by the patient, a seemingly healthy woman, were minor chest discomfort and mild dyspnea upon exertion for the last six month. Cardiac catheterization revealed stenoses of both the right and left pulmonary arteries. Magnetic resonance imaging revealed a mediastinal tumor mass that almost totally compressed the right main pulmonary artery and also encroached upon the left pulmonary artery. Histologically the tumor was a malignant teratoma. The subsequent course of treatment was complicated by cardiac tamponade. With regression of the tumor during therapy the signs of pulmonic stenosis disappeared. In cases with acquired pulmonic stenosis an underlying mediastinal tumor has to be considered.

Adult↗
PubMed1978

[Cytological studies of sputum and bronchial secretions (author's transl)].

Cytological diagnosis was achieved in 89 of 206 (43.2%) malignant lung tumours verified histologically. The quality of cytological material, number of examinations, tumour size and differentiation, as well as careful handling of the material and experience of the cytologist, all influenced the rate of false-negative results. Cytological examination of sputum and bronchial secretions gave a higher rate of detecting malignant lung tumours than histological examination of material obtained by bronchoscopy.

Biopsy↗
PubMed1975

[Prolonging the life of an implanted pacemaker by reducing impulse duration (author's transl)].

The current drain of a pacemaker depends on the electrical charge delivered to the heart during stimulation, the energy being determined by amplitude and width of the stimulating pulse. On investigating how far pulse duration can be shortened without jeopardizing reliability of cardiac stimulation, how much the current drain can be reduced and how this might influence pacemaker life, it was found that pulse width could be reduced to 0.3 ms in over 80% of cases with an increase in pacemaker life, if powered by conventional mercury batteries, to about 60 months.

Electricity↗